Hypertension (HTN) is a major health problem in the U.S. placing some 58 million Americans at increased risk for stroke, myocardial infarction, kidney failure, and peripheral vascular disease. In addition, HTN is associated with subclinical changes in the heart and in the brain. Although pharmacologic management of HTN is often effective, medications are not without complications and untoward side effects. Consequently, there has been a great deal of interest in the development and application of behavioral treatments for the management of HTN. The present study is a single, randomized clinical trial of exercise and weight management with three long term objectives. The first is to evaluate the efficacy of two behavioral interventions--aerobic exercise and weight management--in reducing blood pressure (BP) in people with mild HTN; the second is to examine the mechanisms by which BP is reduced; and the third is to investigate the effects of behavioral treatment on cognitive performance and related aspects of quality of life. Two hundred unmedicated subjects with mild HTN will be recruited through local radio, television, newspapers, public blood pressure screenings, and flyers from the Raleigh-Durham area. As of 11/30/96, we have had a total of 1972 inquiries, 256 of which were initially eligible. Of those 256, 125 passed the screening tests but 15 withdrew before beginning the study. The remaining 105 patients are enrolled currently and 67 have completed the program. Of the 105 who entered the study, 77 (73%) are White, 26 (25%) are African American, and 2 (2%) are Hispanic; 63 (60%) are female and 42 (40%) are male. We expect to enroll about 75 more subjects over the next 1 1/2 years. Volunteers will be randomly assigned to 6 months of moderate aerobic exercise, moderate aerobic exercise with weight management, or a waiting list control group. Subjects will undergo comprehensive evaluations at baseline and at 6 months, in addition to an initial eligibility screening, consisting of a brief physical exam and blood (11 ml.) and urine (10 ml.) sample. Measurements of BP will be obtained in the clinic, during everyday life using ambulatory BP monitoring, and during physical exercise and mental stress testing. BPs will also be obtained at 1 year follow-up. To examine potential mechanisms responsible for BP changes, subjects will undergo glucose tolerance testing (35 ml. of blood ), lipid analysis (15 ml. of blood), studies of heart rate variability, and hemodynamic and neuroendocrine assessments. Because hypertension has been shown to be associated with measurable changes in cognitive function, which may be reversible when BP is normalized, subjects will also complete neuropsychological assessments along with psychometric testing. Finally, the clinical significance of the BP changes will be determined by repeat cardiac echocardiography, as well as by repeated BP testing at baseline, 6 months, and 1 year follow-up. The information obtained from this study will have important practical significance by determining the efficacy of exercise and weight reduction in lowering BP in men and women with mild hypertension, and by assessing the clinical importance of these changes. Moreover, the study has important scientific significance by clarifying the mechanisms that may be responsible for the BP reductions.